Cassava breeders are curious about appropriate breeding strategies utilized to generate elite genotypes with desired complimentary traits or genes from parents used in crossing. Use of appropriate mating design is influenced by a good understanding of the flower biology of the putative parent plants, type of pollination, crossing technique, pollen dissemination, the presence of male-sterility system, the purpose of the project (that is either breeding or genetic studies), and the size of population needed. The objective of this book chapter is to assess the current knowledge on mating designs, their applications and limitations in cassava improvement. This book chapter discusses the floral biology, genetic improvement, breeding procedures and mating designs in cassava. The information utilized in this study were obtained from various sources including documentary search of the journals, books and websites of relevant stakeholder organizations. Empirical findings of selected mating designs in cassava and their impacts were discussed. Findings serve as a good guide for selection of appropriate mating arrangement to obtain useful information on parents and progenies. Findings are relevant to scientists, researchers, scholars, lecturers and other relevant stakeholders.
Part of the book: Cassava
Cassava (Manihot esculenta Crantz), sweetpotato (Ipomoea batatas) and yams (Dioscorea spp.) are important root and tuber crops grown for food, feed and various industrial applications. However, their genetic gain potentials are limited by breeding and genetic bottlenecks for improvement of many desired traits. This book chapter covers the applications and potential benefits of genetic modification in breeding selected outcrossing root and tuber crops. It assesses how improvement of selected root and tuber crops through genetic modification overcomes both the high heterozygosity and serious trait separation that occurs in conventional breeding, and contributes to timely achievement of improved target traits. It also assesses the ways genetic modification improves genetic gain in the root and tuber breeding programs, conclusions and perspectives. Conscious use of complementary techniques such as genetic modification in the root and tuber breeding programs can increase the selection gain by reducing the long breeding cycle and cost, as well as reliable exploitation of the heritable variation in the desired direction.
Part of the book: Genetically Modified Plants and Beyond